Once the weather begins to cool off, you might be thinking about how you’ll prepare your heating and cooling. After all, HVAC costs frequently add up to a significant portion of your monthly electric bill. To learn new ways to reduce costs, some owners take a closer look at their thermostat. Is there a setting they should use to improve efficiency?

Most thermostats come with a ‘Fan’ or ‘Fan On’ setting. But if the fan is running during a typical cycle, what does the fan setting provide for an HVAC system? This guide should help. We’ll share precisely what the fan setting is and whether you can use it to reduce costs over the summer or winter.

Should I Use My Thermostat’s Fan Setting?

For most thermostats, the fan setting indicates that the system’s blower fan stays on. A few furnaces will operate at a low level with this setting, but in general heating or cooling isn’t being generated. The ‘Auto’ setting, conversely, will start the fan through a heating or cooling cycle and shut it off after the cycle is complete.

There are pros and cons to switching on the fan setting on your thermostat, and whether you do or don’t {will|can|should]] depend on your distinct comfort needs.

Advantages to switching to the Fan/On setting:

  • You can keep the temperature in every room more uniform by allowing the fan to keep generating airflow.
  • Indoor air quality can increase as steady airflow will keep passing airborne pollutants into the air filter.
  • A smaller amount of start-stop cycles for the blower fan helps expand its life span. As the air handler is typically connected to the furnace, this means you can prevent the need for furnace repair.

Drawbacks to switching to the Fan/On setting:

  • A constant fan could raise your energy bills by a small margin.
  • Nonstop airflow could clog your air filter up more quickly, increasing the frequency you should replace it.

{Choosing Between|Should My Thermostat Be on|Which Setting for My Thermostat? Fan or Auto in Summer/Winter

In the summer, warm air can linger in unfinished spaces such as the attic or an attached garage. If you use the fan setting, your HVAC system might pull this warm air into the rest of your home, compelling the HVAC system to work harder to preserve the preferred temperature. In extreme heat, this could result in needing AC repair more quickly as wear and tear gets worse.

The opposite can occur in the winter. Cooler spaces like a basement will hold onto cooler air, which can eventually drift into the rest of your home. Leaving the fan running may draw more cold air upward, increasing the amount of heating you need to remain warm.

If you’re still trying to decide if you should switch to the fan/on setting, keep in mind that every home and family’s comfort needs are different. Leaving the HVAC system’s fan on might be best for you if:

Someone in your household suffers from allergies. Allergies and other respiratory conditions can be hard on the family. Leaving the fan on should help to increase indoor air quality, helping your family breathe easier.

Your home deals with hot and cold spots. Many homes wrestle with stubborn hot and cold spots that quickly return to a temperature different from the rest of the house. The fan setting can help lessen these changes by consistently refreshing each room’s supply of air.